A187669 Number of (n+1)X(n+1) 0..2 arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal.

50, 550, 11282, 612204, 65533922, 18950885038

Offset: 1

Author

R. H. Hardin Mar 12 2011

Keywords

• nonn

Comments

Column 2 of A187670

Examples

			Some solutions for 4X4
..1..0..1..2....2..0..2..1....1..1..2..0....2..2..2..2....1..0..1..0
..2..2..0..2....2..1..0..2....1..2..1..2....2..1..0..2....1..2..0..1
..1..0..1..2....2..0..1..1....2..1..2..1....2..0..1..2....1..0..2..1
..0..2..0..2....1..2..0..2....0..2..1..1....1..2..2..2....0..1..0..1